#include <bits/stdc++.h>
// #include <atcoder/modint>
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
#define rep2(i, s, n) for(int i = (s); i < (int)(n); i++)
#define printYN(check) cout << ((check)? "Yes" : "No") << endl
#define NUM 998244353
#define IMAX INT_MAX
#define LMAX LONG_MAX
using namespace std;
// using namespace atcoder;
// using mint = modint998244353;
using vi = vector<int>;
using vvi = vector<vi>;
using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
using vs = vector<string>;
using vb = vector<bool>;
using vvb = vector<vb>;
using pii = pair<int, int>;
using vpii = vector<pii>;
using tii = tuple<int, int, int>;
using mii = map<int, int>;
using Graph = vvi;
// Graph graph(n);
// vi dx = {-1, 0, 1, -1, 1, -1,  0, 1};
// vi dy = { 1, 1, 1,  0, 0, -1, -1,-1};
// snippet -> {UnionFind, dfs_reculsive, dfs_stack, is_prime, mypow, 
//              bfs_queue, digsum, binary_search, gcd, Dijkstra, bitsearch}
// -------------------------------------------------------------------------

int main() {
    string s;
    cin >> s;
    if(s[0] == s[1] && s[0] != s[2]) {
        printYN(1);
        return 0;
    }
    printYN(0);
    return 0;
}